package net.core.service.encrype;


/**
 * TODO 获取CRC检验结果
 * @author xuyanjun
 */
public class CalcCRC {
	private static CalcCRC calcCRC = new CalcCRC();

	/**
	 * 利用单例模式获得该类的对象,利用CaclCRC.getInstance().xxx()调用该类的方法。
	 * @return 本类对象
	 */
	public static CalcCRC getInstance() {
		return calcCRC;
	}

	private char[] crc_tb = { 
			0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5,
			0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad,
			0xe1ce, 0xf1ef, 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294,
			0x72f7, 0x62d6, 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c,
			0xf3ff, 0xe3de, 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7,
			0x44a4, 0x5485, 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf,
			0xc5ac, 0xd58d, 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6,
			0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe,
			0xd79d, 0xc7bc, 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861,
			0x2802, 0x3823, 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969,
			0xa90a, 0xb92b, 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50,
			0x3a33, 0x2a12, 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58,
			0xbb3b, 0xab1a, 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03,
			0x0c60, 0x1c41, 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b,
			0x8d68, 0x9d49, 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32,
			0x1e51, 0x0e70, 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a,
			0x9f59, 0x8f78, 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d,
			0xf14e, 0xe16f, 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025,
			0x7046, 0x6067, 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c,
			0xe37f, 0xf35e, 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214,
			0x6277, 0x7256, 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f,
			0xd52c, 0xc50d, 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447,
			0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e,
			0xc71d, 0xd73c, 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676,
			0x4615, 0x5634, 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9,
			0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1,
			0x3882, 0x28a3, 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8,
			0xabbb, 0xbb9a, 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0,
			0x2ab3, 0x3a92, 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b,
			0x9de8, 0x8dc9, 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83,
			0x1ce0, 0x0cc1, 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba,
			0x8fd9, 0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2,
			0x0ed1, 0x1ef0 };

	/**
	 * 获得CRC值<十六进制ASCII字符串>
	 * 
	 * @param strHex：输入参数String<十六进制ASCII字符串>
	 * @return String CRC检验结果十六进制ASCII字符串
	 */
	public String caluCRC(String strHex) {
		int[] pByte = strToInt(strHex);
		int len = pByte.length;
		char crc;
		byte da;
		crc = 0x0;
		int i = 0;
		while (len-- != 0) {
			da = (byte) (crc / 256);
			crc <<= 8;
			int num = da ^ pByte[i];
			if (num < 0)
				num += 256;
			crc ^= crc_tb[num];
			++i;
		}
		String CRC=Integer.toHexString((int) crc).toUpperCase();
		if(CRC.equals("0")){
			CRC="0000";
		}
		if(CRC.length()==1){
			CRC="000"+CRC;
		}
		if(CRC.length()==2){
			CRC="00"+CRC;
		}
		if(CRC.length()==3){
			CRC="0"+CRC;
		}
		return CRC;
	}
	/**
	 * 获得CRC值<十六进制ASCII字符串>
	 * 
	 * @param str:输入参数，普通String
	 * @return String CRC检验结果十六进制ASCII字符串
	 */
	public String calu_CRC(String str){
		byte[] b=str.getBytes();
		String hs = "";
		String stmp = "";
		for (int n = 0; n < b.length; n++) {
			stmp = (Integer.toHexString(b[n] & 0XFF));
			if (stmp.length() == 1)
				hs = hs + "0" + stmp;
			else
				hs = hs + stmp;
			if (n < b.length - 1)
				hs = hs + "";
		}
		return caluCRC(hs.toUpperCase());
	}

	/**
	 * 获得CRC值<十六进制ASCII字符串>
	 * 
	 * @param pByte：输入参数 byte一维数组
	 * @return String CRC检验结果十六进制ASCII字符串
	 */
	public String caluCRC(byte[] pByte) {
		int len = pByte.length;
		char crc;
		byte da;
		crc = 0x0;
		int i = 0;
		while (len-- != 0) {
			da = (byte) (crc / 256);
			crc <<= 8;
			int num = da ^ pByte[i];
			if (num < 0)
				num += 256;
			crc ^= crc_tb[num];
			++i;
		}
		return Integer.toHexString((int) crc).toUpperCase();
	}

	/**
	 * 将String字符串转化为十进制int型一维数组
	 * 
	 * @param s：输入参数String的十六进制ASCII字符串
	 * @return int[]
	 */
	public static int[] strToInt(String sHex) {
		int[] buf = new int[sHex.length() / 2];
		int j = 0;
		for (int i = 0; i < sHex.length() / 2; i++) {
			buf[i] = Integer.parseInt(sHex.substring(j, j + 2), 16);
			j += 2;
		}
		return buf;
	}
}
